Southern California -- this just in

'Onion Field' killer seeks compassionate release

The state parole board will consider Tuesday whether to release a man known as the "Onion Field" killer, who was convicted in the 1963 kidnapping and murder of a Los Angeles police officer.

Gregory Powell, 77, was convicted of killing on-duty LAPD Officer Ian Campbell and sentenced to death, but the sentence was later reduced to life without parole.

Campbell and his partner, Karl Hettinger, had pulled over Powell and accomplice Jimmy Lee Smith. Powell pulled a gun and disarmed Campbell, then forced Hettinger to give up his weapon.

Powell and Smith took the officers to a deserted onion field near Bakersfield, where Powell executed Campbell. Hettinger escaped.

Joseph Wambaugh wrote the book "The Onion Field" about the case. Smith died in prison in 2007.

Powell, who has prostate cancer, is asking for compassionate release from prison. The union of Los Angeles police officers has opposed his request.

The board of the Los Angeles Police Protective League said in a statement posted on the union's website earlier this month, "It defeats the purpose of a life sentence if, at the end of life, cold-blooded murderers like Powell are let out so their last days can be spent in comfort.

"Part of the deserved punishment for his brutal crime is that he spend his last waking moments deprived of freedom."

The union noted that Powell has been denied parole 11 times since 1972.